<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>flex 实现圣杯布局</title>
    <link rel="stylesheet" href="../css/layout-css/flex.css" />
  </head>
  <body>
    <header>header</header>
    <div class="main">
      <div class="left">left</div>
      <div class="center">center</div>
      <div class="right">right</div>
    </div>
    <footer>footer</footer>
  </body>
</html>
